DS Delfino Square

-After coming out of some of the final buildings, there should be a couple of crates. Immediately after, there's an opening. To cut through the mud, you use a Mushroom. It might be hard at first, but after you've got it down, it really cuts your time.
-Before the bridge, but after you come out of the last building, turn left into a more open area. Use a Mushroom boost to cut through and jump over the river.
-After jumping the bridge, use a Mushroom boost to cut through the grass.